Because the vast majority of electric guitars have solid bodies, the generated sounds are determined, not by the body, but by the pickups and associated controls and amplifiers. Electromagnetic pickup design, in particular, has been the subject of a great amount of effort. In strenuous attempts to achieve what may be called "magic sounds" and thus obtain increased market share, the numerous factors which go into the design of electromagnetic pickups have been varied in an infinite number of ways. These factors include number of turns, size of wire, type and construction (and materials) of magnets, spacing from strings, and so forth.
Electromagnetic pickups for guitars and other musical instruments are inherently resonant in nature. The inductance necessary for resonance is present in the windings, while the capacitance is distributed along the windings as well as being present along the leads to which the windings connect. Different electromagnetic pickups have different "characteristic sounds" determined primarily by their resonance curves. The relative steepness or flatness of the peaks of the curves is important, as is the location of the peaks on the frequency band.
It is conventional for electric guitars to incorporate tone controls which do nothing other than pass, in a controlled way, the higher or lower frequencies in the audio range. Such elements do not permit any true adjustment of the "characteristic sounds" of their associated pickups. In fact, such elements have in the past done relatively little to satisfy the desires of musicians.